Lifting-jack



A. A.- STROM.

LIFTING JACK.

(N oV Model.)

No. 385,885. Patented July 10, 1888.

rviTnn STATns iATnNT @r1-reno AXEL A. STROM, OF AUSTIN, ILLINOIS.

LlFTiNG-JACK.

SPECIFICATION forming part of Letters Patent No. 385,885, dated July 10.1898- Application filed March 16, 189B.

Serial No 2613605 (No model.)

T o argl whom-it may concern:

E 'it known that l, AXEL A. S'rRoM, a citizenjof the United States,residing at Austin, in the county of Cook and State of Illinois, haveinvented a new and useful Improvement in Lifting-Jackspf which thefollowing is .a speciication. v

.My invention relates to an improvement in the class of lifting-jacksemploying a frictione'lut'ch device on the lifting-bar through which toactuate and control 'the bar, and my object is to provide a simple,reliable, and positively-y aeting'friction-clutch for the lifting-bar.

' improvement; and Fig. 2 shows the collar of the friction-clutch insection on a broken piece of the lifting-bar, with the pivotal wedgeduplicated to act against opposite sides of the lifting-bar, andprovided with links (shown broken) for connection of the pivotal wedgeswith the operating-lever. l

A is the lifting-jack, having the standard portion B and lifting-bar C,of .common construction, and a lever, D, fulcrumed, as shown, ina box,t, on the upper end towardthe rear side of the expanded portion of thestandard, whereby its short arm extends toward the lifting-bar. N earthe end of the short arm of the lever D, on oppositesides thereof, arepivoted links s, only one of which is shown, however, in Fig. 1, owingto the nature of the view, though the construction will readily belinderstood, being common, without detailed illustration of the twolinks.

Eis the lifting-clutch, comprisinga collar, r, surrounding thelifting-bar, containing a wedge, q, pivoted to it at one inner side andprojecting therefrom. against the adjacent side of the lifting-bar. Theform of the pivotal wedge is prcferabi shown-that is, tapering towardits pivotal end and convex vertically at its daring end, with the Lipperportion of the rounded extremity normallyiu contact with thelifting-bar, whereby continued raising of the wedge on its pivotincreases its binding effect against the bar, and thus augmente thefriction hold of the clutch. The flaring end of the pivotal wedge mayobviously, however, be straight vertically. A perforated c ar, p, maybeprovided on the upper-edge of the pivotal we'dge, Vto which the lowerend of the link or links s is pivoted, whereby the pivotal wedge isattached to the short arm of To this end my invention consists in acollar the lever D.

lever the wedge is raisedon its pivot and wedged againstI the sido ofthe lifting-bar, thus also raising the bar by the grip exertedpositively by the direct connection of the wedge with the lever, whichgrip is also to a material extent augmented by the downward pressure orgravity of the met-al collar, the

tendency-of which is to have the same effect,l

as the raising of the wedge on its pivot, alread described. l

E is the retaining-clutch, substantially ofthe same construction as theylifting-clutch, inasmuch as it has a collar, r', surrounding thelifting bar, (preferably vbelow the liftingclutch, as shown,) and awedge, g', pivoted toI one side of the collar and extending against theadjacent side of the lifting-bar. There is, however, no link-connectionforl the pivotal wedge, as in the. case of the lifting-clutch; but itrests at the lower edge of therounded fiaring'extremity, or towardthelower corner,upon the base of the expanded upper portion of thestandard B, and thus, and by its normal pressure against the barproduced by the weight of the collar, sustains or forms the support forthe latter. Vhen the bar is raised by the vlifting-clutch, the effect onthe lower clutch is,

by the friction of the outerand lateral side of the collar thereofagainst the bar, to raise the last-named collar, and thus release thebinding effect of the retaining-clutch pivotal wedge, thereby permittingthe bar to slide upward, the retaining-clutch being held down by .itsown weight, while, after the bar has been raised and the lifting-clutchlowered for a fresh grip, the downward pressure of the load causes theretaining-clutch to grip and hold IOO the bar by the friction of thelatter against the collar, which tends to lower it and thus force thesupported pivotal wedge more and more firmly against the bar.

To release the retaining-clutch for the purpose of permitting thelifting-,bar to be lowered, Iprcvideabifurcated lever, F, the prongs ofwhich extend from beyond a fulcrum, a, o r pivot on the base of the'upper expanded .por-

tion of the standard B, below' opposite lateralf sides of the collar, orby any suitable means into the desired contact therewith, and the handleportion m of which projects beyond the rear side ofthe standard, whereit is readily accessible. Downward pressure on the handle-moi the leverF raises the collar of the retaini 11g-clutch, and thus releases itsgripping efi'ect on the bar, which can then slide down to its normalcondition gradually, if the fall be controlled by a resisting powerexertedl upon' the lever D, or suddenly, if the collar of theliftingclutch be stopped by contact with the stops Z and Z', provided onthe standard to be engaged by opposite ends orV sides of the collar. v

If desired, the` pivotal Wedges may be d'uplicated, as shown in Fig. 2,to extend from opposite sides or ends of the collar against the adjacentsides of the lifting-bar, when of "course the links or pairs of linkssare also du-l plicated vand the lever D bifurcated as to its short arm,for proper connection of the links s with it, as is common inliftingjacks.

What I claim as new, and desire to secure by l Letters Patent, is-

l. In a lifting-jack, the combination, with thelifting-bar, of acollant', a wedge, q, pivoted to one side of the collar and extendinginto contact Withthe lifting-bar and releasable by downward lpressureupon the pivot vfrom its Wedging engagement with the lifting-bar,lale-ver, D, fulcrumed upon the standard and linked to the Wedge betweenits pivot and end in contact Withthe bar, and a retaining-clutch on thelifting bar and supported on the standard, substantially as described.

2.l In a liftingjack, the combination; with the lifting-bar and alifting-clutch having an operating-lever connected with it, of aretaining-clutch, E', comprising a collar and a Wedge pivoted to one side ofthe collar and extending into contact with the lifting-bar, and withf ofthe collar and extending into contact with the lifting-bar, a lever, D,connected with .the pivotal wedge toward its free end. and aretaining-clutch, E', comprising a collar and a Wedge pivoted to oneside of the collar and extending into contact with the lifting-bar andwith a stationary support, substantially as described. 4

4.' In a lifting-jack, the combination, with the lifting-bar, ofalifting-clutch, E, comprising' a collar and a wedge pivoted to'one sideof the collar and extending into contact with the lifting-bar, a lever,D, connected with the pivotal Wedge toward its free end, aretainingelutch, E', comprising a collar and a wedge pivoted tov oneside of the ,collar and extending intocontact With theliftingbar andwith the base olif-the expanded upper portion of thc standard, and atially as described.

5. A lifting-jack comprising, in combi nation, a standard, B, alifting-bar, C, a liftingclutch, E, comprising a collar and a wedgepivoted to one side of the collar and extending into contact with thelifting-bar, a lever, D, links s, connecting the lever'witli the pivotalwedge-toward its free end, a retaining-clutch, E', comprising a collarand a wedge pivoted to one side of the collarand extending into contactwith the liftingbar and with the base of the expanded upper portion ofthe standard, and a lever, F, fulcrumed on the standard and extendinginto enga-gement with the collar of the retainingclutch to permit thesaid collar to be raised when desired, substantially as,

described. l

` Ax EL A. srRoM.

releasinglever, F, snbstan-

